In the last ten years, numerous studies have demonstrated the major role played by melatonin (5-methoxy-N-acetyltryptamine) in the control of the circadian rhythm and of endocrinal functions. In addition, melatonin receptors have been characterised and located.
In addition to their beneficial action on circadian rhythm disorders (J. Neurosurg. 1985, 63, pp 321-341) and sleep disorders (Psychopharmacology, 1990, 100, pp 222-226), ligands for the melatoninergic system have valuable pharmacological properties in respect of the central nervous system, especially anxiolytic and antipsychotic properties (Neuropharmacology of Pineal Secretions, 1990, 8 (3-4), pp 264-272) and analgesic properties (Pharmacopsychiat., 1987, 20, pp 222-223) and also for the treatment of Parkinson's disease (J. Neurosurg. 1985, 63, pp 321-341) and Alzheimer's disease (Brain Research, 1990, 528, pp 170-174). Those compounds have also exhibited activity in respect of certain cancers (Melatonin--Clinical Perspectives, Oxford University Press, 1988, pp 164-165), ovulation (Science 1987, 227, pp 714-720) and diabetes (Clinical Endocrinology, 1986, 24, pp 359-364), and in the treatment of obesity (International Journal of Eating Disorders, 1996, 20 (4), pp 443-446).
Compounds providing a means of acting on the melatoninergic system are accordingly excellent medicaments for the clinician for the treatment of pathologies associated with the melatoninergic system, especially those mentioned above.